1. Field of the Invention
The present invention relates to an optical detector for flowing sample and an optical detection method for flowing sample.
2. Description of the Related Art
In a general prior art for analyzing a sample an optical detector for flowing sample is frequently used. The optical detector for flowing sample irradiated a light from a light source to the sample made to flow in a light transmitting flow path before detecting the light having passed the sample. The sample then is analyzed on the basis of results of the detection.
In the prior art for leading a light from a light source to a light transmitting flow path, a slit is arranged before the light transmitting flow path, the light from the light source is converged at the slit before coming in the light transmitting flow path, and after that the light is irradiated to the sample.
As the light is converged before the light transmitting flow path in that way, the light is minimized in the cross-sectional area when it passes the slit before passing the light transmitting flow path while being diverging. The prior art is disadvantageous in that parts or all of the light beam are reflected or absorbed by the inside walls of the light transmitting flow path or the slit.
Another known prior art has a light transmitting flow path formed so as to track along a diverging light beam. The prior art can solve the disadvantage that the light beam is reflected or absorbed by the inside walls of the light transmitting flow path. However, the prior art cannot prevent the light beam from being reflected or absorbed by the slit still. The prior art also has such a disadvantage that since diameter of the flow path is different at positions, the density distribution of the liquid pressure is dispersed. This results in deviation of the track of the light beam.
In view of the foregoing, it is an object of the present invention to provide an optical detector and detection method for flowing sample that can solve the problems of difficulties in the light path.